6s.
All the others on two machines are fine…but this…ouch
So I am going to test the motor and replace the ESC…dang
Hello @darrell
Thank you for the great information provided by you.
I wanted to know which camera and lens do you use for the mapping purpose and what are the results obtained on you rig?
Also can you tell the accuracy of your maps using this rig and also the altitude you usually fly on?
Thanks for help
much appreciated
Cheers!
Shubham Thakur
I use a Sony A6000 with 16mm pancake lens. I fly at 120 meters high which gives me about 4cm/pixel resolution. I’ve only done a few maps with the Skywalker as most of my work is done with a multi rotor. I’m still experimenting with doing larger areas with fixed wing.
Hello!
First of all, thank you so much for sharing the details of your work! We are in the process of building a Skywalker X8 frame into a VTOL, and your posts have been a huge help.
I was trying to open that .wdf file you posted with the 3D model of the wing extensions, but after some googling I still could not figure out how to open it. Do you have the file in any other format, or could you point me in the right direction for opening the file you posted?
Thanks,
Bernhard
It will take me a while to chase up a file that a friend used recently. He said he got it from Thingiverse but I don’t see any there. However, there seems to be quite a few on GrabCAD https://grabcad.com/library?page=1&time=all_time&sort=recent&query=skywalker%20x8
Hi Darrell, I’ve attached a wing extension template I use. It’s provided in a few different CAD file formats. May help.
X8 Foam Wing Extension.zip (299.8 KB)
Cheers
2 Likes
That’s, appreciate it.
Thank you guys! Appreciate it.
@darrell
Hi i am trying a skywalker x8 vtol build myself. Can i just ask you, have you got the air frame set up as an H or X quad config. I initially had mine in an x but i found yaw and air frame twist caused an issue where i would end up with very little yaw control. (ended up flipping and snapping a section off the wing) I read somewhere that the flex in an H configuration would help. I have patched the wing and now setup in H config with FR motor going CCW etc i now have a good hover but have not tried transition yet to FBWA as not sure if i should stay in H or X config. Your help would be appreciated. Also if you dont mind what do you have set for pitch roll and yaw pids ?
Thanks in advance.
I’ve always set up mine as X. Wing twist and poor yaw authority are common issues. What’s your hover percentage? Quadplanes typically need a lot of power to hover which causes issues with not having enough power left for yaw. Maybe @rmackay9 could provide some feedback about this. A few other people have asked me what I think about mounting the motors so they are pointing outwards a few degrees like some commercial copters do. That might help yaw but I’m not really sure.
I don’t know much about quadplanes but I think the idea of using an H setup (which is the same as X except the motors spin in the opposite direction) is a good idea. The flex of the wings should contribute to the vehicle yawing instead of fighting against it. Of course the controllers would be happiest if there wasn’t any flex in the wings.
I agree the power-to-weight ratio is important. Making sure there’s enough power left for yaw control would help I think.
I’m not so keen on the idea of leaning motors because it will introduce a coupling between roll, pitch and yaw and I suspect it will make balancing the thrust across the motors difficult. I.e. some will be leaning slightly more than the others and will lead to control problems.
Thanks for that i am using tmotor mn3110 780kv currently on 4 cell with 14 inch carbon props but the motors are getting a bit warm after a 4
min hover so think i will have to look into that. Due to me mounting a 3d printed CF round tube holder directly under the wings there was a slight incline so i have a 20 degree forward printed part on front motors and 10 degree backwards on the rear. This did improve stability and yaw control. I also tried a slight outward pitch so in essence the props were slightly pushing away from the centre line but that didn’t change much. throttle is about 80% hover i’m concerned with motor heat build up. All on 4S lipo currently but on separate power supply’s. Might try 6s on the copter motors but need to get some new esc’s.
i do have good hover now and yaw is better in the H config probably more nerves now trying the transition
Did you leave pids at 4.5 or much of a change for you ?
sorry all for the dodgy wiring as its my first attempt i wanted to know would it hover first this will all be cleaned up.
I guess the question is do i go to 6s on the quad motors and then get rid or the pitch on the motors as this can induce more issues than were solved in hover. Transition could maybe cause an issue with that pitch as i have not tried fast forward flight just hovering around really ? Or maybe go for a higher KV motor or bigger prop on the 6S ?
Hello again, @darrell!
Would it be possible to provide som details on the wiring? It would be really helpful to see a picture of how you have wired the two circuits up. In particular I have these questions:
- For the circuit with the four top motors: How do you split ut the two wires from the battery into four?
- For the circuit with the four top motors: After splitting up the wires, do you connect each of the four wires directly to the ESCs?
- For the circuit with the front motor: Do you connect the battery to the power module, and then take the 10 or 12 awg wires and connect them directly to the front ESC?
- How do you connect both of the two current sensors (both the power module for the top circuit and the front circuit) to the Pixhawk?
Thanks in advance. I really appreciate your help!
Bernhard
First of all there are build photos here that might help you a bit.
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I use a XT-90 connector which can easily hold two 12 gauge wires to create a Y cable that provides two pairs of power that goes to two XT60 connectors. Then I use one on each side of the plane.
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No. I have a XT60 connector to the ESCs which the above wires connect to.
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The ESC for the rear motor is at the rear of the build. The battery is at the front. Before the wiring gets to the ESC I have a power module plugged in with a XT90 connector.
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I use a Mauch power sensor for the vertical lift motor circuit. It’s connected to the Pixhawk via the ADC 3.3 volt port. See this link for instructions on how to wire up two power connectors.
I’m rebuilding my Skywalker so I’ve taken a photo of the quadplane wiring for you.
Hi Darrel! Thanks, that helps.
What changes are you making to your Skywalker build this time around?
Bernhard
Same configuration. I saw an ad for a ‘obsidian’ version of the Skywalker which apparently is made out of a denser foam that makes it stiffer so I ordered one. A friend of mine cut some wing extensions for me out of a material that cuts more like wood and is very light and dense so I’ve already made the wing extensions out of that. Other than that I’ll just take my time and try to make it all a bit cleaner of a build.
Here’s what the wiring looks like in the fuselage. This is the top half. I think most people prefer to have their ESCs close to the motors to keep them cool. Given that the vertical motors aren’t on long I haven’t had issues with heat buildup in the fuselage. But I do have them mounted for maximum air flow around all sides.
I see, sounds like you are making some improvements! Thanks for the picture of the wiring. What is the donut-shaped object that you are wrapping your servo wires around?
Also, where did you order the new Obsidian version of the Skywalker from? I can’t seem to find it.
The rings are ferrite rings. The ESCs came with them. Wrapping a wire around a metal ring like that is a common way to reduce signal noise.
I think the term ‘Obsidian’ is just a marketing term they now use for the black version. The one I just received is no different than those I’ve received in the past. The older version has larger squared off wing tips. But I think those haven’t been sold in some time so you should get a new one just by ordering black.
They now have more fibre in the wings and the black foam is a bit stiffer than the white. Many people don’t like the black though as it’s considered harder to see in the air. Personally I find it easier to see in the sky although if it flies past a dark cliff face it can all but disappear from view. But overall I don’t have issues with visibility.